This application relates generally to medical and biological adhesives and more particularly, to methods for bond or sealing living tissues within a patient's lungs using a phosphate-based adhesive.
Conventional methods of closing incisions in soft tissue, such as lung tissue, following surgery and injury, for example, include the use of sutures and/or staples. However, as is known, the use of such surgical methods may be limited. For example, depending on the tissue being repaired, the sutures or stitches may provide an inadequate seal of the tissue resulting in undesirable leakage of fluid or air along the line of joinder. Moreover, such surgical procedures generally require significant surgical skill and may be slow to apply.
To facilitate reducing the likelihood of fluid leakage through a tissue being repaired, at least some surgical methods use a laser to weld or fuse adjoining tissues together. However, the heat necessary to cause the tissue fusion may also cause collateral thermal damage. Moreover, the edges of tissues damaged by the treatment may enable fluid leakage therethrough. As such, because of the risk of transmural and/or collateral thermal injuries, such surgical methods generally require the use of highly-skilled surgeon.
Accordingly, to facilitate the fluid-tight or air-tight sealing of a wound without the issues described above, at least some known surgical procedures use adhesives or glues that are capable of bonding tissue surfaces together rapidly while promoting, or at least not inhibiting, normal healing. For example, at least some known tissue adhesives are fibrin-based and contain a concentrate of fibrinogen and thrombin. Such adhesives are generally two-component adhesives that when mixed together, react to simulate a clot-forming cascade that adheres to tissue and bridges a gap defined between adjoining portions of tissue until healing can occur. However, fibrin-based adhesives may have only limited success because of their low strength and because of the risk of infection associated with the harvesting of fibrin from human blood.
Other known tissue adhesives are based on gelatin being cross-linked with aldehyde, such as gelatin-resorcinol cross-linked with formaldehyde (GRF) or with glutaraldehyde (GRFG). However, the inclusion of aldehyde may cause tissue irritation during use. Moreover, such glues may time-consuming and difficult to use because of the criticality of obtaining the proper cross-linking at the joinder site.
Adhesives found in nature, as well as laser light-induced tissue adhesives have also been used. However, the use of natural product-based adhesives have generally been limited because of the difficulties in purifying appreciable quantities of such materials and the risks associated with triggering an immune response by foreign glycoproteins.
The use of synthetic materials to expedite sealing of tissue is common in the course of surgical procedures concerned with the repair of damaged tissues and vessels. However, generally the adherence of known adhesives used in the repair of tissues in lungs, for example, may be difficult where the tissue surface to be treated may be wet, or covered with blood, mucus, or other secretions. If fluid is present on the surface being repaired, known adhesives may delaminate from the surface after its formation. Moreover, generally known tissue adhesives may lack sufficient mechanical strength (i.e., adhesive properties), may become brittle and/or may not have a sufficient elasticity when formed, and/or may not be biocompatible.